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The light-independent phase is the Calvin cycle, also called the Calvin-Benson cycle. It happens in the chloroplast stroma and uses carbon dioxide along with energy from ATP and reducing power from NADPH, which are produced during the light-dependent reactions. Because it doesn’t require light itself, it can run as long as ATP and NADPH are available. In this cycle CO2 is fixed into a three-carbon sugar, ultimately forming sugars such as glucose that the plant can store or use for energy. This phase is separate from the light-dependent reactions, which capture light to make ATP and NADPH and release oxygen, and from other pathways like glycolysis and the Krebs cycle that occur in respiration.